Pseudostegana sigangli, Gong & Chen, 2018

Gong, Lu & Chen, Hongwei, 2018, Seven new species of the genus Pseudostegana (Diptera: Drosophilidae) from South-west China, with DNA barcoding information, Journal of Natural History 52 (31 - 32), pp. 2097-2119 : 2116-2118

Pseudostegana sigangli sp. nov.

( Figures 5 (g–l) and 12)

Diagnosis

This species is most closely related to P. montipagana sp. nov. in the wing pattern and male terminalia ( Figure 12), but can be distinguished from it by the ocellar triangle, scutum and aedeagus; in this species, ocellar triangle narrowly elongated to anterior margin of frons ( Figure 5 (j)); scutum yellow on anterior two-thirds, brownish yellow on posterior one-third ( Figure 5 (k)); aedeagus apically acute in lateral view ( Figure 12 (c)). The 10.6% interspecific genetic distance to P. montipagana is the smallest within this group; there are 12 diagnostic sites between P. sigangli sp. nov. and P. montipagana sp. nov. ( Figure 2).

Description

Male. Head ( Figure 5 (g,j)): Ocellar triangle and frons brownish. Pedicel and first flagellomere yellow. Face brown. Palpus yellow, broadened in male, medially one-third as wide as long. Clypeus black. Gena brown. Thorax ( Figure 5 (h,k)): Pleura nearly brown. Katepisternal setae three. Scutellum brownish, pale at tip. Legs: Yellow, brownish on basal half of tibiae of mid and hind legs. Abdomen ( Figure 5 (l)): All tergites nearly black. Sternites yellow on second and third, brownish to dark brown on the rest. Male terminalia ( Figure 12): Epandrium roundly protruding on ventral margin, with about 17 setae per side. Surstylus protruding on posteroventral corner. Cercus ventrally round. Paramere apically bifurcated, subapically with two long sensilla and several sensilla on dorsal projection. Basal process of aedeagus slender, apically about six finger-like projections.

Measurements

BL = 3.33 mm, ThL = 1.30 mm, WL = 2.83 mm, WW = 1.27 mm, arb = 7/1, avd = 1.23, adf = 1.63, flw = 1.88, FW/HW = 0.45, ch/o = 0.08, prorb = damaged, rcorb = 0.19, vb = 0.83, dcl = damaged, sct1 = damaged, sterno = damaged, orbito = 0.70, dcp = 0.14, sct1p = 1.45, C = 2.26, 4c = 1.53, 4v = 3.53, 5x = 1.38, ac = 11.50, M = 0.73, C3F = 0.76.

Type material

Holotype male ( SCAU No. 111430), China: Mengdong, Cangyuan , Yunnan, 23.169°N, 99.231°E, altitude 1320 m, 16 May 2016, ex tussock, L. Zhu.

Etymology

The name means ‘Va community is coming out of the grotto’, from a legend of the Va nationality endemic in Cangyuan, Yunnan.

Distribution

China (Yunnan).